The conventional methods for fabricating such parts are pressureless sintering, hot-isostatic pressing, and hot pressing. See Raj et al. U.S. Pat. Nos. 4,487,840 and 4,552,711.
Pressureless sintering is accompanied by non-uniform shrinkage which makes it impossible to meet close tolerances without substantial machining.
Hot-isostatic pressing requires the use of a cladding to separate the pressurizing gas from pores of the powder compact and produces product where flaws are retained.
Hot pressing normally is utilized to press into pancake or billet shapes which are machined into final shape.